Friday, 4 January 2013

Megacity is a term used to describe a
city which has a population over 10 million. In 190 there were only 4
megacities, in 2010 there were 24 and it is estimated that by 2015 there will
be nearly 30 megacities, half of which in Asia.

Explain the factors that have
led to emergence of megacities (9)

Cities need high population growth in the city and the
surrounding areas (this supplies migrants to the city) to grow. The population
boom in many countries only started a few decades ago, especially after the
Second World War the population growth increased. Large rates of rural-urban
migration among young adults plus increased natural increase due to advances in
technology and health services. Better hygiene leads to a higher natural
increase and an increase in life expectancy. City dwellers are able to
specialise which increases the productivity. Cities are sited on trade routes
which provide good communication, for example rivers roads and railways.

There is a reduced need for agricultural labour combined
with the loss of farm land. Greater productivity in the agricultural sector
means fewer workers are needed and greater opportunities in the city. Growing industrialisation
poor farming methods and climate change all contribute to the loss of farm
land, for example China looses 3-6 thousand sq km of agricultural land each
year.

Similar specialised activities, like banking, will cluster
together in cities this leads to a large pool of workers which leads to an
increased efficiency. This creates a multiplier effect which is the idea of
momentum, once a city gains success it leads to more success. There are more
jobs so more people come which means there are more people who need goods and
services, which creates more jobs, and the cycle goes on.

Economies of Scale show that there are advantages to be
gained from one megacity instead of many smaller cities. In Megacities there
are financial savings to be made from transport, communication between people
and businesses will be easier. Better schools will be located in cities this
means there is a better educated workforce in cities. These people increase the
overall productivity of the city raising its GDP. The city dwellers now have a
high level of education are rich and are diverse this leads to more cultural
activity which can be a consumer good. This also leads to greater economic
development, this also attracts migrants.

Megacities contribute a large proportion of the country’s
economic activity for example Bangkok has around 10% of the population but
contributes around 30% of the GDP for Thailand.

3. Describe
the problems associated with megacities (6)

Use your textbook, the geofile on megacities, our newspaper
article and the link to the market place notes here. Make sure
that you use the textbook pages 149-151 and the Geoactive

In Megacities there is a high competition for land which
leads to land being expensive and unable to meet demand. This leads to s
greater amount of high rise flates. These reduce the availability of green
spaces and can diminish the quality of life for those living there. In LIC
cities many of the rural to urban migrants are looking for cheap, low cost
housing, this is why millions of people live in temporary shanty towns and
squatter settlements. Slums can be built on hazard-prone land and lack basic
services like health education sanitation and transport. This means that in
Slums there is ill-health, low life expectancy and crime.

In Megacities congestion is an issue as walking or cycling
to work is not really an option. Designing a transport system takes time and
money. Public transport systems are much more space efficient than cars.
However it is not easy to plan as megacities grow fast and in an unplanned way.
London has tried to control the problem by introducing the Congestion Charge. In
Sao Paulo they have found a solution, they have the most complex bus system in
the world today. They have many bus lanes. Everywhere in the city is on a bus
route. This means that the bus travels faster than cars.

A lot of energy and resources are used in cities. Many LICs
and MICs are not connected to the national grid, or connected unsafely. Only
50% of people have piped portable water and these are the cities there the
population is growing the fastest.

There is a social segregation which leads to an opportunity
gap. Poorer city dwellers do not have access to the same opportunities and
services. Large cities encourage criminal activity because it is easier to
hide. Megacities have serious quality of life issues but as megacities keep on
growing the positives must outweigh the negatives.